Phosphorus Loads Upstream (Arkansas) and Phosphorus Loads Upstream (Arkansas) and Phosphorus Loads Upstream (Arkansas) and Downstream (Oklahoma) Of Lake Frances:Downstream (Oklahoma) Of Lake Frances:Downstream (Oklahoma) Of Lake Frances:

Are Differences Due to Are Differences Due to Are Differences Due to Monitoring Program Design, Natural Variation, Monitoring Program Design, Natural Variation, Monitoring Program Design, Natural Variation,

or The Lake?or The Lake?or The Lake?

Thomas SoerensThomas SoerensThomas SoerensUniversity of ArkansasUniversity of ArkansasUniversity of Arkansas

Acknowledgements

GimGim GohGoh, UA Civil Engineering, UA Civil EngineeringBrian Haggard, UA/USDABrian Haggard, UA/USDA

OutlineBackground and historyBackground and history•• Illinois River in Oklahoma and ArkansasIllinois River in Oklahoma and Arkansas•• Lake Frances Lake Frances

Possible differences between AR and Possible differences between AR and OK loadsOK loads•• LakeLake•• VariationVariation•• Monitoring programMonitoring program

Summary, conclusions, futureSummary, conclusions, future

Oklahoma and Arkansas

Linco ln

Fayetteville

Springdale

Rogers

SiloamSprings

W estville

S tillwell

Ark 04A

Ark 05

Ark 06

Ark 06A

Ark 07

W atts

Kansas

TallequahEldon

Oklahom a Arkansas

W ater sam pling sites

Illinois River in Arkansas-Oklahoma

USGS 03-4168

Lake Frances

Lake Frances

AROK

AR hwy 59 sampling site

OK hwy 59 sampling site

2.5 km

Loads upstream of lake different than loads downstream?

Illinois River - background

Designated as an Oklahoma scenic riverDesignated as an Oklahoma scenic riverIllinois River and Lake Illinois River and Lake TenkillerTenkiller in in Oklahoma are major recreational areasOklahoma are major recreational areasImpacted by point sources and Impacted by point sources and nonpointnonpointsources in Arkansassources in ArkansasLawsuit between Oklahoma and Arkansas Lawsuit between Oklahoma and Arkansas reached the U.S. Supreme Courtreached the U.S. Supreme Court

Background: Illinois River - LawsuitOklahoma sued Arkansas (1986)Oklahoma sued Arkansas (1986)•• to stop Fayetteville dischargeto stop Fayetteville discharge•• U.S. Supreme Court 1992:U.S. Supreme Court 1992:

–– AR must meet OK water quality standardAR must meet OK water quality standard•• No P limits in Arkansas except FayettevilleNo P limits in Arkansas except Fayetteville

–– ARAR--OK Arkansas River Compact CommissionOK Arkansas River Compact Commission•• oversees agreementoversees agreement

Compact commission recommendationsCompact commission recommendations•• Arkansas Reduce Phosphorus by 40%Arkansas Reduce Phosphorus by 40%

–– use avg. load from 1980 to 1993 as baselineuse avg. load from 1980 to 1993 as baseline–– use 5 year moving use 5 year moving avgavg

•• Note: lawsuit began over point sources, focus has Note: lawsuit began over point sources, focus has shifted to shifted to nonpointnonpoint sourcessources

Northwest ArkansasAbundant water resourcesAgricultural productionPopulation growthUrban development

Agricultural Productionin NW Arkansas

Lake Frances - History1931 – wooden dam completed, resort opens• golf, tennis, swimming, horses, boating, dancing, fishing

1943 – embankment partially washed out1954 – Siloam springs purchases lake, rebuilds dam, builds treatment plant1971 – concerns about lake water quality1977 – Lake “in late stages of eutrophication”

1978 – concerns about safety of damEarly 1980s – Fayetteville, AR proposes WWTP discharge into Illinois River1983 – Lake Frances clean lakes study• Point sources = 65% of P load

1985 – study it again.

Lake Frances - History

1983 Lake Frances study

Total P “declines only slightly” between Total P “declines only slightly” between upstream and downstream stations.upstream and downstream stations.Form of total P:Form of total P:•• 85% in reactive form upstream85% in reactive form upstream•• 54% in reactive form downstream54% in reactive form downstream“…sedimentation is eliminated as a “…sedimentation is eliminated as a major net phosphorus sink.”major net phosphorus sink.”Study focused on Study focused on baseflowbaseflow

1985: “…officials were urged … to ensure that special interests don’t influence the results of two studies…”

1985: “…challenged what he called omissions and discrepancies in the studies and urged that differences between the studies be reconciled…”

1983: “…60 to 90 percent of pollutants in Lake Frances come from (Arkansas) plants’ discharge…”

1983: “…estimate was flawed by faulty sampling methods and did not give enough blame (to NPS)…”

Lake Frances - HistoryLate 1980s –

March 12, 1990 Article…

Lake Frances gets really nasty• shallow and mucky, boats running aground• Algae in lake and downstream• EPA study: “…Lake Frances outflow was the most

turbid water sampled in the Illinois River Basin.”

Dam is unsafe. Court order to repair dam by July 1, 1990

The Oklahoman, March 12, 1990

“shallow, polluted mud hole”

“…creates a foul odor and clouds the Illinois for 12 miles”

OSRC: “… have Lake Frances declared a public nuisance and drained. … either fix it or take it out.”

“… dredge it…”

“… open the gates…”

Lake Frances - HistoryMay 4, 1990 – Dam busts• Top several feet break off

Lake Frances – before 1990

Lake Frances – after 1990

Lake Frances – after dam break

What’s happening in “lake”now?Lots of nutrient rich sedimentLots of nutrient rich sedimentPhosphorus flux?Phosphorus flux?

Why would lake make a difference?P source or sinkP source or sinkBallard Creek (~10% of flow)Ballard Creek (~10% of flow)•• Unnamed creekUnnamed creek

Illinois River concentrations and loads

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

119

89

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

year

C (m

g/L)

0

50000

100000

150000

200000

250000

300000

load

(kg/

yr)

AR mg/LOK mg/LAR loadOK load

0.037 mg/L OK standard

Why would loads be different?

Effects of Lake FrancesEffects of Lake Frances•• The lakeThe lake•• Two streams between sampling stationsTwo streams between sampling stations

Natural variation and errorNatural variation and errorMonitoring program designMonitoring program design

Lake sampling 4 sites, sampled same time4 sites, sampled same time

0.0000

0.0500

0.1000

0.1500

0.2000

0.2500

8/12

/200

3

9/2/

03

9/16

/03

9/31

/03

10/1

4/03

10/2

8/03

11/1

1/03

11/2

5/03

12/1

2/03

12/2

5/03

SRP

(mg/

L)

AR 59 BridgeOK 59 BridgeBallard Creek"little creek"

Soluble Reactive PSoluble Reactive P

Sediment sampling – P flux

A whole A whole lottalotta P flux going onP flux going on•• Anaerobic: ~ 16 (mg/mAnaerobic: ~ 16 (mg/m22)/day)/day

–– 16 is 16 is eutrophiceutrophic, Lake , Lake EuchyEuchy is 4is 4

•• Aerobic: 0.2 Aerobic: 0.2 –– 4 4 –– Very highVery high

A lot of high nutrient sedimentA lot of high nutrient sediment

Variation Sampling and load calculationSampling and load calculation

(USGS 03-4168)

USG

S

AWR

C

15 d

ay u

p 50

15 d

ay Q

onl

y

15 d

ay 9

sto

rm

15 d

ay n

o st

orm

30 d

ay u

p 50

30 d

ay Q

onl

y

30 d

ay 9

sto

rm

30 d

ay n

o st

orm

45 d

ay u

p 50

45 Q

onl

y

45 9

sto

rm

60 d

ay u

p 50

60 d

ay Q

onl

y

60 d

ay 9

sto

rm

Tota

l Pho

spho

rus

Annu

al L

oad

(kg)

100

150

200

250

300

350

400

450

500 Estimator results

60 day15 day 30 day 45 day

For each sampling period, boxes left to right are:•9 storms from upper 50% of flow

•9 storms, upper 50%, no seasonality•9 random storms

•no storms (15 and 30 day)

t hou

sand

95% CI

Variation – flow calculation

400

500

600

700

800

900

1,000

1,100

1,200

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

avg

flow

(cfs

)

AR FlowOK Flow

Monitoring Program Design

Loads for Illinois River agreementLoads for Illinois River agreement•• AR: Monthly sampling; Load = flow*CAR: Monthly sampling; Load = flow*C•• OK: now doing targeted storm sampling OK: now doing targeted storm sampling

(USGS)(USGS)

Also:Also:•• USGS USGS –– ArkansasArkansas•• AWRC AWRC -- autosamplerautosampler

Monitoring program designOklahomaOklahoma

Year Storm sampling

Regression years

coeff. for Q

Load (kg)

Flow-wt C (mg/L)

1998 None 87876 0.138

1999 Start 1997-1999 0.703 130314 0.184

2000 Full 1998-2000 1.09 197346 0.341

2001 Full 1999-2001 1.12 241702 0.417

SummaryLake FrancesLake Frances•• A lot of PhosphorusA lot of Phosphorus--laden sedimentladen sediment•• Not an obvious source or sink of P, Not an obvious source or sink of P,

–– But a source now that point sources are down?But a source now that point sources are down?•• Tributaries not significantTributaries not significantVariationVariation•• Load differences within error/variationLoad differences within error/variation•• Doesn’t explain trendsDoesn’t explain trendsMonitoring Program designMonitoring Program design•• OK is getting more accurateOK is getting more accurate•• OK changes may explain trendOK changes may explain trend

Conclusions (opinion)

Lake can be a longLake can be a long--term source of Pterm source of PDifferences between stations due to:Differences between stations due to:•• Monitoring program differencesMonitoring program differences•• Variation and errorVariation and error

Future - monitoring

New proposed monitoring plan for New proposed monitoring plan for whole Illinois River watershedwhole Illinois River watershed

Future – Lake Frances

Plant something (cattails?)Plant something (cattails?)•• Probably too much troubleProbably too much troubleDredgeDredge•• Good idea, but who pays? Why?Good idea, but who pays? Why?Blow up (rest of dam)Blow up (rest of dam)•• Potential sediment spike worth it?Potential sediment spike worth it?

–– It’s not much of a lake nowIt’s not much of a lake now

Leave it aloneLeave it alone•• likelylikely