July 22, 2004July 22, 2004

Aquifer Storage Recovery is an Alternative Water Supply Aquifer Storage Recovery is an Alternative Water Supply in Southwest Floridain Southwest Florida

Presented byPresented byMark Mark McNealMcNeal, PG /CH2M HILL, PG /CH2M HILL

Presented at thePresented at the

FCOC 18th Annual FCOC 18th Annual Environmental Permitting Environmental Permitting

Summer SchoolSummer SchoolMarco Island, FloridaMarco Island, Florida

Three primary types of ASR projects Three primary types of ASR projects are in operation in Southwest Floridaare in operation in Southwest Florida

Potable Water ASRPotable Water ASRReclaimed Water ASR Reclaimed Water ASR Partially Treated Surface Water ASRPartially Treated Surface Water ASR

Reclaimed WaterReclaimed WaterASR ProjectASR Project

Potable WaterPotable WaterASR ProjectASR Project

Partially TreatedPartially TreatedSurface WaterSurface WaterASR ProjectASR Project

ASR Projects in ASR Projects in Southwest FloridaSouthwest FloridaSt. Petersburg

Manatee Co.

Englewood

Peace River

Tampa

Marco Lakes

Manatee County had the first ASR wells Manatee County had the first ASR wells to come on line in Floridato come on line in Florida

Two ASR wells Two ASR wells completed in 1983 at completed in 1983 at Lake ManateeLake Manatee–– Stores treated surface Stores treated surface

water from the Manatee water from the Manatee RiverRiver

–– Storage zone is relatively Storage zone is relatively fresh, at upper limits of fresh, at upper limits of drinking waterdrinking water

Recently expanded to 6 wellsRecently expanded to 6 wells–– Approximately 10 mgd ASR capacityApproximately 10 mgd ASR capacity–– Demonstrates success of ASR in this areaDemonstrates success of ASR in this area

The Peace River Facility relies on its ASR The Peace River Facility relies on its ASR system to meet itsystem to meet it’’s dry weather demandss dry weather demands

Treated surface water (alum)Treated surface water (alum)PRF recently expanded from PRF recently expanded from 12 to 24 mgd12 to 24 mgd18 mgd current demand18 mgd current demand

12 ASR wells installed 12 ASR wells installed near reservoir in last near reservoir in last expansion (21 total wells)expansion (21 total wells)No dam on the river, flow No dam on the river, flow based withdrawal schedulebased withdrawal schedule

King

King

’’ s H

ighw

ays

High

way

(SR7

69)

(SR7

69)

ReservoirReservoir

Peac

e Ri

ver

Peac

e Ri

ver

SR761SR761

PRMRWSA

PRMRWSA

Boundary

Boundary

Railroad

Railroad

SS--88 SS--77

SS--66 SS--9R9R

SS--5R5R SS--3R3R

TT--11SS--22

SS--11

APAP--11

LEGENDLEGENDInitial ASR WellsInitial ASR WellsAvon Park Test WellAvon Park Test WellASR ExpansionASR Expansion

00 500500 10001000

Largest ASR system in eastern US Largest ASR system in eastern US Additional expansion underway Additional expansion underway --up to 26 additional ASR wellsup to 26 additional ASR wells

WF#2

WF#1

The Peace River system is another ASR The Peace River system is another ASR success story in SW Floridasuccess story in SW Florida

The older ASR wells were evaluated as The older ASR wells were evaluated as the initial step of the ASR expansionthe initial step of the ASR expansion16 years of operational data were reviewed to 16 years of operational data were reviewed to determine effectiveness of ASR WF #1determine effectiveness of ASR WF #12.5 BG of water was stored at the site, and 2.5 BG of water was stored at the site, and ++2 2 BG was recovered over a 2BG was recovered over a 2--year periodyear period

During the drought, During the drought, water up to10 years water up to10 years old was recovered old was recovered The ASR system The ASR system was considered to was considered to be operating be operating satisfactorilysatisfactorily

10 years

Storage zone selection is becoming an Storage zone selection is becoming an important decision for many ASR facilitiesimportant decision for many ASR facilities

Many utilities are faced with a decision Many utilities are faced with a decision --expand outward or utilize multiple zonesexpand outward or utilize multiple zonesCompeting users or impacts to sensitive surface Competing users or impacts to sensitive surface water bodies more likely in shallower zoneswater bodies more likely in shallower zonesRecovery efficiencies may decrease as deeper, Recovery efficiencies may decrease as deeper, more brackish zones are utilizedmore brackish zones are utilizedCertain zones may be more apt to experience Certain zones may be more apt to experience geochemical changes than othersgeochemical changes than othersStacking wells may help control Stacking wells may help control upconingupconing

The Suwannee The Suwannee Zone is the primary Zone is the primary storage interval at storage interval at Peace RiverPeace River

GeologicGeologicUnitUnit

HawthornHawthornGroupGroup

TampaTampaZoneZone

SuwanneeSuwanneeZoneZone

OcalaOcalaLimestoneLimestone

AvonAvonParkPark

FormationFormation

TDSTDS(mg/L)(mg/L)

500

900

2900

00

200200

400400

600600

800800

10001000

12001200

14001400

16001600

Dep

th in

Fee

tD

epth

in F

eet Twenty (20) Twenty (20)

Suwannee Zone Suwannee Zone ASR wellsASR wells

SS--77

575’

915’Typical

SuwanneeZone Well

12”TT--11

380’

482’

TampaZoneWell

12”

One (1) Tampa One (1) Tampa Zone ASR wellZone ASR well

APAP--11

550’

950’

1300’

1479’1504’Backplugged with Cement

Avon ParkWell

20”30”

12” SteelCasing to 1300’

One (1) Avon One (1) Avon Park Zone ASR Park Zone ASR test welltest well

1 m

gd

1 m

gd

3 m

gd

Six alternatives are Six alternatives are being considered being considered for 38 mgd firm for 38 mgd firm capacitycapacity

Existing WUP Existing WUP scenario is a scenario is a dispersed WF in the dispersed WF in the Suwannee ZoneSuwannee Zone5 other scenarios 5 other scenarios consider various consider various spacings, locations, spacings, locations, and storage and storage intervalsintervals

Cost estimates were prepared for each of Cost estimates were prepared for each of the 26the 26--well ASR expansion scenarioswell ASR expansion scenarios

Construction costs equate to Construction costs equate to about $0.50 to $0.70 per mgd about $0.50 to $0.70 per mgd of ASR capacityof ASR capacityAssuming 100 MG storage per Assuming 100 MG storage per well, $5k to $7k /MG storedwell, $5k to $7k /MG stored

The existing WUP layout was The existing WUP layout was the most expensive alternative the most expensive alternative at $17.3Mat $17.3MThe other five scenarios ranged The other five scenarios ranged from $13M to $15Mfrom $13M to $15M

King

King

’’ s H

ighw

ays

High

way

(SR7

69)

(SR7

69)

ReservoirReservoir

Peac

e Ri

ver

Peac

e Ri

ver

SR761SR761

PRMRWSA

PRMRWSA

Boundary

Boundary

Railroad

Railroad

LEGENDLEGENDInitial ASR WellsInitial ASR WellsAvon Park Test WellAvon Park Test WellASR ExpansionASR Expansion

Care must be taken that future Care must be taken that future expansions do not impact existing ASR expansions do not impact existing ASR well performancewell performance

00 500500 10001000

SS--88 SS--77

SS--66 SS--9R9R

SS--5R5R SS--3R3R

TT--11SS--22

SS--11

APAP--11

TampaTampa’’s potable water ASR systems potable water ASR system

Tampa has constructed Tampa has constructed its initial systemits initial system–– 88--well, 10 mgd system well, 10 mgd system –– Constructed in an urban Constructed in an urban

settingsettingTampa is exploring Tampa is exploring ASR expansion options ASR expansion options in the Avon Park Fmin the Avon Park Fm

Scale in Feet

0 500 1000Monitor WellASR Well

Water resources are stressed in the Tampa areaWater resources are stressed in the Tampa area–– Alternative Alternative

water supplies water supplies under under developmentdevelopment

–– A successful A successful ASR system ASR system would provide would provide benefits not benefits not only to the City, only to the City, but to the but to the region as wellregion as well

The City of Tampa has faced several The City of Tampa has faced several challenges with their ASR programchallenges with their ASR program

Geology is Geology is ““leakierleakier”” in this area relative to the successful in this area relative to the successful ASR systems to the southASR systems to the south–– Upconing of saline water from below occurs during recoveryUpconing of saline water from below occurs during recovery

Other geochemical changes have also been observedOther geochemical changes have also been observedReturning water to the WTP has allowed aggressive Returning water to the WTP has allowed aggressive recoveryrecovery

0

50

100

150

200

250

0 25 50 75 100 125 150 175 200Volume Recovered (mg)

Chl

orid

e

Cycle 1

Cycle 3 Cycle 2

ASR-1HillsboroughCounty ASR Well

Limestone

Limestone/Clay

Limestone/Clay

ClayClaySand

Semi-ConfiningZone

Semi-ConfiningZone

Limestone/Clay

Limestone/Clay

Semi-ConfiningZone

Semi-ConfiningZone

ExistingStorage Zone

ExistingStorage ZoneLimestoneLimestone Native Water Quality

Water Use Permitting has also been Water Use Permitting has also been challenging for Tampachallenging for Tampa Numerous domestic Numerous domestic

well owners (none well owners (none have been impacted)have been impacted)Potential for sinkholes Potential for sinkholes in an urban area (none)in an urban area (none)Lake level responsesLake level responsesUrban wetlands?Urban wetlands?Withdrawal schedule Withdrawal schedule to allow rechargeto allow recharge–– How to bank water How to bank water

during wet years to during wet years to recover during dry yrsrecover during dry yrs

–– Rolling Rolling avgavg not allowednot allowedFluctuating chloride Fluctuating chloride concentrations in ASR concentrations in ASR wells and wells and MWsMWs

LAKES

Chloride concentrations show temporary Chloride concentrations show temporary response during recoveryresponse during recovery

Chloride in nearby storage zone Chloride in nearby storage zone MWsMWs increases from 20 increases from 20 to as high as 850 mg/Lto as high as 850 mg/L

0

200

400

600

800

1,000

Sep-01 Dec-01 Mar-02 Jun-02 Sep-02 Dec-02 Mar-03 Jun-03 Sep-03 Dec-03 Mar-04

Chl

orid

e C

once

ntra

tion

(mg/

L

SMW-1 SMW-2 SMW-3 SZMW-1 SZMW-2SZMW-3 SZMW-4 SZMW-5 Series9

Start 2002 Recovery Start 2003 Recovery

r = 150'

r = 190'

Once recharge Once recharge begins, storage begins, storage zone freshenszone freshensNo noticeable No noticeable impact to shallow impact to shallow (domestic) zone (domestic) zone --no impacts to no impacts to adjacent usersadjacent users

Geochemical changes have been monitored Geochemical changes have been monitored closely and are showing improvementclosely and are showing improvement

Certain metals from the host rock (e.g., Fe, Certain metals from the host rock (e.g., Fe, MnMn, As) are , As) are released due to differences between recharge water quality & released due to differences between recharge water quality & groundwatergroundwater

Dissolved oxygen Dissolved oxygen in the recharge in the recharge water appears to be water appears to be major contributormajor contributorProgress is being Progress is being made following made following multiple cyclesmultiple cyclesVery localized Very localized phenomenonphenomenon

0

10

20

30

40

50

0 25 50 75 100 125 150Volume Recovered (mg)

As C

once

ntra

tion

(ppb

)

Chloramine disinfectant Ozone disinfectant

Cycle 3

Cycle 4

Tampa has also had many successesTampa has also had many successes……......

Able to coAble to co--exist with residentsexist with residents–– No impacts to private well ownersNo impacts to private well owners–– No sinkholes linked to ASR No sinkholes linked to ASR pumpagepumpage–– No ASRNo ASR--related impacts to neighborhoodrelated impacts to neighborhood

Lake level responses not typical ofLake level responses not typical ofgroundwater production in this areagroundwater production in this area–– Surficial water level impacts insignificantSurficial water level impacts insignificant–– attributed to deeper well casing settingsattributed to deeper well casing settings

and cyclical nature of ASR operationsand cyclical nature of ASR operations

Able to provide about 15 percent of the CityAble to provide about 15 percent of the City’’s water s water supply during the 2000supply during the 2000--2002 drought2002 droughtCOCO22 treatment to increase ASR well capacitytreatment to increase ASR well capacity

TampaTampa’’s carbon dioxide treatment has s carbon dioxide treatment has effectively replaced well acidizationeffectively replaced well acidization

Initial investment of about $1,000 for COInitial investment of about $1,000 for CO22 equipmentequipmentNow costs about $100 per CONow costs about $100 per CO22 event vs. $25kevent vs. $25k--$30k for $30k for acidizationacidization–– No byNo by--products products

requiring disposalrequiring disposal–– No chloride increase No chloride increase

@ ASR wells@ ASR wells–– No pump removalNo pump removal–– No kiddingNo kidding

Increased Increased injectivityinjectivityfrom less than 1 to from less than 1 to 40 gpm/psi40 gpm/psi10 MG recharged in 10 MG recharged in 1 week vs. 3 months1 week vs. 3 months

ASR-5 (Following Carbon Dioxide Treatment)

0

10

20

30

40

50

9/15/03 10/6/03 10/27/03 11/17/03Date

Spec

ific

Inje

ctiv

ity (g

pm/p

si

Pre-CO2

Post-CO2 2nd CO2 application

Acid.exe Co2.exe

Status of Southwest Florida Status of Southwest Florida reclaimed water ASR projectsreclaimed water ASR projects

Operational testing has been initiatedOperational testing has been initiated–– Englewood Water District & Hillsborough Co.Englewood Water District & Hillsborough Co.

Constructed and ready to start testingConstructed and ready to start testing–– St. Petersburg & Manatee CountySt. Petersburg & Manatee County

Others permitted to construct systemsOthers permitted to construct systems–– City of Sarasota, Sarasota Co., Lehigh AcresCity of Sarasota, Sarasota Co., Lehigh Acres

In the feasibility study/permitting phaseIn the feasibility study/permitting phase–– Pinellas Co., Clearwater, Largo, and othersPinellas Co., Clearwater, Largo, and others

EnglewoodEnglewood’’s reclaimed s reclaimed water ASR system is water ASR system is undergoing testingundergoing testing

Permit issued in 1999 Permit issued in 1999 --renewal underwayrenewal underwaySystem constructed at WWTP System constructed at WWTP in 2000in 2000–– Storage zone 500 to 700 feet blsStorage zone 500 to 700 feet bls–– Storage zone was saline (20,000 Storage zone was saline (20,000

mg/L TDS)mg/L TDS)Began operational testing in Began operational testing in July 2001July 2001Required an exemption for Required an exemption for color color -- other other DWSsDWSs were metwere metInitial cycle testing has been Initial cycle testing has been limited but is encouraginglimited but is encouraging

Cycle testing has posed challenges for EWDCycle testing has posed challenges for EWD

Timing can be challenging for Timing can be challenging for reclaimed water ASRreclaimed water ASR–– CanCan’’t add reuse customers without ASRt add reuse customers without ASR–– CanCan’’t test w/o sufficient reuse demandt test w/o sufficient reuse demand

ResultResult: A deep injection well was : A deep injection well was constructedconstructed–– Will allow EWD to perform more Will allow EWD to perform more

aggressive cycle testingaggressive cycle testing–– Some water will be wasted to confirm Some water will be wasted to confirm

well performancewell performance

WWTP &ASR Site

ReuseCustomers

0

100

200

300

400

500

Jun-01 Oct-01 Feb-02 Jun-02 Oct-02 Feb-03 Jun-03 Oct-03 Feb-04

Volu

me

Stor

ed (m

g)

Actual Storage Volume Proposed Cycle Testing

The WWTP was a zero discharge facility, The WWTP was a zero discharge facility, with reuse accounting for all dischargeswith reuse accounting for all dischargesEWD is EWD is seweringsewering the area, with flows the area, with flows increasing significantlyincreasing significantlyAdditional reuse customers have been brought Additional reuse customers have been brought online within the past yearonline within the past yearEWD has 500 MG in storage, as reuse EWD has 500 MG in storage, as reuse demand has not kept up with supplydemand has not kept up with supply

The City of St. PetersburgThe City of St. Petersburg’’s s ASR program is linked to ASR program is linked to its DIW systemits DIW system

Located at its Southwest WRFLocated at its Southwest WRF–– Freshening in overlying zonesFreshening in overlying zones–– Storage zone previously 30,000 Storage zone previously 30,000

mg/L TDS, now 5,000 mg/L TDSmg/L TDS, now 5,000 mg/L TDSSolute transport modeling Solute transport modeling suggests this will improve early suggests this will improve early recovery efficiency from 3% to recovery efficiency from 3% to an estimated 35% an estimated 35% Recovery endpoint expected to Recovery endpoint expected to be 1,500be 1,500--2,000 mg/L TDS2,000 mg/L TDSCycle testing will begin soonCycle testing will begin soon

Solute Transport Model OutputSolute Transport Model Output

St. Petersburg ASR siteSt. Petersburg ASR site

SummarySummaryASR systems are alive and well in Southwest FLASR systems are alive and well in Southwest FLASR allows effective use of our major rivers and ASR allows effective use of our major rivers and surplus reclaimed watersurplus reclaimed waterApproximately 40 mgd capacity among top 3 Approximately 40 mgd capacity among top 3 potable potable water ASRwater ASR systems in southwest FL, with several systems in southwest FL, with several other smaller ASR systems as wellother smaller ASR systems as wellReclaimed water ASRReclaimed water ASR projects are advancing due to projects are advancing due to the seasonal variations between supply and demandthe seasonal variations between supply and demandOnly one Only one partially treated surface water ASRpartially treated surface water ASR site is site is in operation, but others are anticipated in the futurein operation, but others are anticipated in the futureAlthough each program has its challenges, ASR Although each program has its challenges, ASR remains a very cost effective, safe alternative water remains a very cost effective, safe alternative water supply option with supply option with significantsignificant importance to SW FLimportance to SW FL

July 22, 2004July 22, 2004

Aquifer Storage Recovery is an Alternative Water Supply Aquifer Storage Recovery is an Alternative Water Supply in Southwest Floridain Southwest Florida

Presented byPresented byMark McNeal, PG /CH2M HILLMark McNeal, PG /CH2M HILL

Presented at thePresented at the

FCOC 18th Annual FCOC 18th Annual Environmental Permitting Environmental Permitting

Summer SchoolSummer SchoolMarco Island, FloridaMarco Island, Florida