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Long-term Long-term Monitoring of the Monitoring of the Des Moines RiverDes Moines River
Donna S. LutzDonna S. LutzDes Moines River Water Quality Des Moines River Water Quality
NetworkNetwork
Presented at the Des Moines Water Works January 28, 2008
What is the Des Moines What is the Des Moines River Water Quality River Water Quality
Network?Network?
• Initiated in July 1967 as preimpoundment study for Saylorville Reservoir, expanded to Red Rock Reservoir in 1971
•Long-term record, 40 years at many sites, total of 252 parameters, about 485,000 individual data records
• Currently 7 regular sampling sites, monitored 22 times per year for up to 50 parameters
•Data available through annual reports, paradox database, & project webpage
Des Moines River Basin•Length 535 mi•Width 50 mi•Basin 12,884 sq mi
about ¼ size of IowaSaylorville
Reservoir•24 mi valley/54 mi flood•5,520 acres/ 16,100 flood•1,100 ac-ft/yr sedimentationRed Rock Reservoir•18 mi valley/33 mi flood•15,250 acres/ 1,625,00 fl•4,470 ac-ft/yr sedimentation
Raccoon River Sub-basin
North Raccoon/Middle Raccoon/South RaccoonBasin 3,411 sq mi
Routine ParametersRoutine ParametersRoutine ParametersRoutine Parameters
PhysicalPhysical temperature, flow/elevationtemperature, flow/elevation turbidity, secchi disc depth, gas turbidity, secchi disc depth, gas
saturationsaturation ChemicalChemical
dissolved oxygen, BOD, TOC, nutrients, dissolved oxygen, BOD, TOC, nutrients, suspended solidssuspended solids
metals, pesticidesmetals, pesticides BiologicalBiological
chlorophyll pigmentschlorophyll pigments bacteriabacteria
Important Programs: Important Programs: Short-termShort-term
BacteriaBacteria River, reservoir and River, reservoir and
beachesbeaches Is it safe to swim, wade?Is it safe to swim, wade?
State of Iowa WQ StdsState of Iowa WQ Stds Based on E ColiBased on E Coli Class A1 & A3 Class A1 & A3 (1(1o o & &
children)children) geomean 126 /100mlgeomean 126 /100ml Sample max 235 /100mlSample max 235 /100ml
Class A2 Class A2 (2(2o o contact)contact) geomean 630/100mlgeomean 630/100ml Sample max 2,880 /100mlSample max 2,880 /100ml
Bacteria Monitoring
Important Programs: Important Programs: Short-termShort-term
Are they safe to eat?Are they safe to eat? For people and crittersFor people and critters
Cyprinus carpioCyprinus carpio Fillets Fillets (28 yr) (28 yr) Whole Whole (20 yr) (20 yr)
Dieldrin, Chlordane, Dieldrin, Chlordane, Heptachlor epoxide, Heptachlor epoxide, Alachlor, Trifluralin Alachlor, Trifluralin and Chlorpyrifosand Chlorpyrifos
Electrofishing on Iowa River
Pesticides in Pesticides in FishFish
Important Programs: Important Programs: Short-termShort-term
Fish Kill InvestigationsFish Kill Investigations Thermal StressThermal Stress
Dorosoma cepedianumDorosoma cepedianum Large kills, one species, Large kills, one species,
similar sizesimilar size Gas SupersaturationGas Supersaturation
Minor to large kills, Minor to large kills, many species and size many species and size rangesranges
Either extreme gas Either extreme gas pressure or lowered pressure or lowered outflowoutflow
Important Programs: Important Programs: Short-termShort-term
What’s Up?What’s Up? Why is water so Why is water so
foamy?foamy? Oily?Oily? Green?Green?
Important Programs: Important Programs: Long-termLong-term
What is normal?What is normal? Is water quality Is water quality
improving? improving? (degrading or can’t (degrading or can’t tell?)tell?)
Major PlayersMajor Players NutrientsNutrients PesticidesPesticides ChlorophyllChlorophyll BacteriaBacteria WQIWQI
Significant FindingsSignificant FindingsSignificant FindingsSignificant Findings
Non-point sources are the main Non-point sources are the main contaminantscontaminants;; soil erosion and siltation primary resource soil erosion and siltation primary resource
problemproblem Ave. loading to Red Rock 5,400 metric Ave. loading to Red Rock 5,400 metric
tons/daytons/day
Point source loading has decreasedPoint source loading has decreased Improved wastewater treatment has significantly Improved wastewater treatment has significantly
reduced ammonia loadingreduced ammonia loading
Nitrate levels have increased, Nitrate levels have increased, with the with the greatest increases seen 1967-1986, paralleling greatest increases seen 1967-1986, paralleling increases in N fertilizer use increases in N fertilizer use
Total Phosphate levels have Total Phosphate levels have decreased slightlydecreased slightly, , but only by about 0.01 but only by about 0.01 mg/yearmg/year
Significant Findings Significant Findings (cont’d)(cont’d)
Overall, Overall, water quality has significantly water quality has significantly improvedimproved at most sites, at most sites, according to water according to water quality index valuesquality index values
Pesticide levels in fish are lowPesticide levels in fish are low, , but may still but may still be of concernbe of concern
Gas supersaturation-induced gas Gas supersaturation-induced gas bubble traumabubble trauma causes periodic fish kills below causes periodic fish kills below Red Rock DamRed Rock Dam
DMRWQN WebsiteDMRWQN Website
http://te-webserver.cce.iastate.edu/research/lutz/dmrwqn/dmrwqn.htmlhttp://te-webserver.cce.iastate.edu/research/lutz/dmrwqn/dmrwqn.html
Project description, site Project description, site photosphotos
Monitoring event data, Monitoring event data, monthly & annual reportsmonthly & annual reports
Beach bacteria dataBeach bacteria data Long-term data available from Long-term data available from
Lutz or websiteLutz or website Acknowledge source, ie RI Acknowledge source, ie RI
CorpsCorps Provide us with analysis or Provide us with analysis or
reportreport
Monitoring Event Report
Annual Report
Focus on Nitrite +Nitrate Focus on Nitrite +Nitrate NN
Ammonia oxidized to nitrateAmmonia oxidized to nitrate (bacterially mediated)(bacterially mediated) Nitrite, intermediate product, (1967-76, max 0.68 mg/l, Nitrite, intermediate product, (1967-76, max 0.68 mg/l,
99% of samples <0.20 mg/l)99% of samples <0.20 mg/l) SourcesSources
Fertilizers, oxidation or organic N, fixation of NFertilizers, oxidation or organic N, fixation of N22, , precipitation, sewage effluentsprecipitation, sewage effluents
LossesLosses Leaching, assimilation living organisms, conversion to Leaching, assimilation living organisms, conversion to
other formsother forms Soluble, Soluble, easily leaches from soileasily leaches from soil
TRANSFORMS & MOVES with WATERTRANSFORMS & MOVES with WATER
1900 1920 1940 1960 1980 2000
Tot
al D
isch
arge
(in
)
0
5
10
15
20
25
1900 1920 1940 1960 1980 2000
Bas
eflo
w D
isch
arge
(in
)
0
5
10
15
1900 1920 1940 1960 1980 2000
Sto
rmflo
w D
isch
arge
(in
)
0
5
10
15
1900 1920 1940 1960 1980 2000
Bas
eflo
w P
erce
ntag
e
20
30
40
50
60
70
80
Results – Streamflow Results – Streamflow ChangesChanges
Regression Models Regression Models Relating Baseflow to Relating Baseflow to
NitrateNitrate
Qb provided best r2 value (0.61) compared to Q (0.59), Qs (0.48) or Q% (0.27)
What is normal?What is normal?
Des Moines River at Boone Des Moines River at Boone 40 yr annual average, 5.86 mg/l 40 yr annual average, 5.86 mg/l
Raccoon River at Van Meter Raccoon River at Van Meter 35 yr annual average, 7.07 mg/l35 yr annual average, 7.07 mg/l
→ → Was 2007 water year Was 2007 water year unusual?unusual?DMR 7.11 mg/l Raccoon R 9.58 mg/lDMR 7.11 mg/l Raccoon R 9.58 mg/l
Are nitrate Are nitrate concentrations concentrations
increasing?increasing?
Data is not normally Data is not normally distributed so used non-distributed so used non-parametric statisticsparametric statistics Loftis and Ward, Colorado Loftis and Ward, Colorado State University - tested 7 State University - tested 7 statistical tests Recommend statistical tests Recommend Seasonal Kendall testSeasonal Kendall testData was flow-adjusted – Data was flow-adjusted – influence of climatic events influence of climatic events removedremoved
Need to use statistical Need to use statistical techniques to discern and techniques to discern and describe trendsdescribe trends
Seasonal Kendall Tau Trend Analysis, Significant Trends (95%)(from Monthly Mean Data, flow-adjusted)
Des Moines River near Boone NO2+NO3 N 1972-2007 1972-1986 1986-1997 1997-2007 n 425 163 133 129 mean 6.16 6.21 6.00 6.36 slope no trend no trend no trend +0.26 Raccoon River near Van Meter NO2+NO3 N 1972-2007 1972-1986 1986-1997 1997-2007 n 377 163 133 129 mean 7.07 6.83 7.22 7.81 slope +0.05 + 0.21 no trend +0.15
NO2+NO3 N
Nitrogen Fertilizer Use and Corn Acres Planted 1964- 2006
Raccoon R at Van Meter, Recent data shows increasing trend 0.14 mg/l/yr*but only at 90% confidence
DMR at Boone, Recent data shows increasing trend 0.26 mg/l/yr
What this means to What this means to DMWWDMWW
Nitrate concentrations Nitrate concentrations are increasing in the are increasing in the Raccoon River, Raccoon River, currently at a rate of currently at a rate of 0.15mg/l/yr0.15mg/l/yr
Is the 10 mg/l drinking Is the 10 mg/l drinking water standard being water standard being exceeded more often? exceeded more often? Yes, in the Des Moines Yes, in the Des Moines River, maybe in the River, maybe in the Raccoon River.Raccoon River.
Overall, is water quality Overall, is water quality better?better?
Yes, according to WQIYes, according to WQI DMR WQI based onDMR WQI based on
%DO (0.21)%DO (0.21) pH (0.14)pH (0.14) BOD (0.14)BOD (0.14) NONO22+NO+NO3 3 (0.13) Ammonia (0.17) Turbidity + Sus Solids
(0.21)
If interested contact me about statistical methods employed
