High nitrate concentrations in midwestern streams

HighNitrateConcentrationsinMidwesternStreamsin2013Following

the2012Drought

Jeff Frey – IN WSCPete Van Metre – TX WSCUSGSNational Water-Quality Assessment Program (NAWQA)

NAWQACycle3– 2013‐2022• NationalFixedStationNetwork 100streamsmonitoredforlong‐termtrends

• RegionalStreamQualityAssessments Intensivesingleseasonstudies

• PrincipleAquiferSurveysGroundwaterquality• IntegratedWatershedStudiesGW‐SWrelationsinafewsettings

• Forecasting Modelsofsurface‐ andground‐waterqualityandeffectsonaquaticecology

RegionalStreamQualityAssessments• Status of the stream quality in the region• Relations between stressors and ecological

condition• Relations between environmental setting and

stream quality • Spatially explicit predictions of stressors and

ecological responses regionally

Midwest Stream- Quality Assessment• USGS National Water Quality Assessment• USEPA Office of Pesticides Program• USEPA National Rivers and Streams Assessment

MSQA components• Geographic distribution and seasonal changes in stressors

• Contaminants, nutrients, and sediment in water seasonally• Contaminants in bed sediment• Contaminants in time-integrating samplers• Toxicity of sediment and water

• Ecological conditions• Ecological sampling at all sites and regional estimates of

condition• Modeling/prediction

100 MSQA Sites• Match our sampling to

NRSA’s first 50 random sites• Fill out stressor gradients

with 50 targeted sites:• Reference – 21 sites• Urban – 12 sites• Trend and other

high-priority sites – 17 sites

West

South

East

Blue – randomGreen – refYellow – other agRed -- urban

100 MSQA sites

Des Moines Water WorksNews ReleaseHistoric Nitrate Levels in Des Moines Water Works’ SourceWaterTuesday, May 28, 2013Nitrate concentrations continue to remain exceptionally high in both the Raccoon and Des Moines Rivers. Through extensive and expensive water treatment, Des Moines Water Works’ finished drinking water is currently under the Environmental Protection Agency’s (EPA) maximum contaminant level (MCL) of 10 milligrams per liter (mg/l) and is safe for drinking.

High nitrate concentrations in Iowa caused expensive and unintended consequences

2012 was a drought followed by a wet springIowa

NAWQA Trend and MSQA site

Eastern study area: 2012 was a drought but wetter earlierIndiana


2013 - Spatially the highest nitrate concentrations were in IA and MN

2013 - Spatially the highest nitrate concentrations were in IA and MN

Long-term data Comparison• Northeast-Midwest Institute

• NWIS/STORET - existing• Searched out additional state, local datasets• Included only data from May-July 1990-2012 (~81,000

NO2+NO3 samples)• Need to quality assure data

• Removed sites outside MSQA study area (OK)• All high values were checked with appropriate agency and

removed if needed• Removed all data with “tile”, “Lake”, “inlet”, “outlet” in

name• Final number of NO2+NO3 samples (~35,300)

Historically, Median Nitrate Concentrations were similar or lower in 2013 except for western states: IA, MN, SD

Compared to long term sampling in Iowa the May-July concentrations were the highest ever


Compared to long term sampling in Indiana the May-July concentrations were the 6th highest ever


Compared to long term sampling in Nebraska the May-July concentrations were the 10th highest ever


High nitrate related to high spring streamflowand fall drought conditions

MSQA site

DischargeNitrate

At the Indiana site antecedent conditions were much lower than in Iowa

MSQA site

Discharge

Nitrate

Summary and Future Analysis• Nitrate concentrations were high in 2013 in a wet spring

that followed a drought year in 2012• Highest concentrations – high 30 to low 40 mg/L

• High concentrations followed a west to east regional pattern • This corresponded to the highest loading and longest

drought period• The highest concentrations were in IA and MN in 2013 but

also historical data suggesting drought was only a part of the high nitrate values in 2013

• Correlate streamflow and rainfall with nitrate data

Information and ContactsNAWQA – USGS http://water.usgs.gov/nawqaOPP – USEPA http://www.epa.gov/pesticides/NRSA – USEPA http://water.epa.gov/type/rsl/monitoring/riverssurvey/index.cfm

Jeff Frey(317) 600-2751 [email protected] Van Metre(512) 927-3506 [email protected]

All 12 visits, water samples:Major ions or Cl/SO4 Nutrients Suspended sediment conc.Pesticides Glyphosate (IA) 17-estradiol (IA)

Three visits, Chlorophyll a, phytoplanktonFinal visit, sediment samples:

Major and trace elements Pesticides (CUPs)OC and radionuclides Toxicity testing

POSIS, deployed for final 6 weeks, all samples analyzedCurrent-use pesticides

SPMD, deployed for final 6 weeks but not all will be analyzed

Final visit, sediment samples:Halogenated compoundsPAHs and other SVOCs

Pankow daily water samplers and weekly composite (4 ag, 3 urban)

EPA to analyze for pesticidesNWQL weekly composite split

Final visit, tissue samples:Halogenated compoundsCurrent-use pesticides

Sampling at all 100 sites

27 intensive sites: 12 ag, 12 urb, 3 ref

10 sites: Pankow/tox 5 ag, 5 urban8 sites: caged fish/frog

SPMDs analyzed Halogenated compoundsPAHs and other SVOCs

Caged fish and frogs, CERCreproductive endpoints and biomarkers

Final visit, Ecological survey

Every other visit, grab water sample: MeHg and THg

71 sites: NRSA Hg Every other visit, water sample

Hormones (NWQL)Glyphosate (KSWSC)

Every other visit whole water (10 sites)

Water toxicity (CERC)Suspended and filtered CUPs

Final visit, fish tissue plug for Hg by NRSA

6 sites: continuous Continuous DO, N, etc. monitors

Additional periphyton