A nutrient mass balance of Fernan Lake, ID, and future directions Frank M. Wilhelm and Trea LaCroix Department of Fish and Wildlife Sciences, University of Idaho, Moscow ID fwilhelm@uidaho.edu 208-885-7218 CDA tributaries WAG meeting, Nov 30, 2015, CDA, ID Funded by:
Acknowledgements • Coeur d’ Alene wastewater treatment plant • IDEQ • FLCRA • Bill Miller • Marie Pengilly • Mike Webb F. Wilhelm • Susan Andrews Funding provided by Idaho EPSCoR # IIA-1301792 M.Pengilly
Outline • Background • Fernan Lake intro • Mass balance • Internal loading • Future directions
Lake Classification Trophic state Oligo- Meso- Eutrophic F. Wilhelm http://fitpacking.com/images/CLNP/CraterLakeAerial.jpg
Eutrophication • Eutrophication: presence of excess nutrients that stimulate aquatic plant growth (Schindler et al. 2008) • Human activities accelerate this process ag, forestry, roads https://www.idahoecosystems.org/cda
What causes blooms? C arbon :N itrogen :P hosphorus N:P 7.2:1 (by mass) N:P = 7 = balanced
TN:TP ratio (by mass) • Theoretically N:P > 7 = P-limited - OK N:P < 7 = N-limited - problems • In reality Cyanobacteria blooms and toxins when N:P 75:1 or less T.Harris
600 (W. CDN) n=40 Zurawell (unpublished) 500 (AUS) n=48 Ghadouani (unpublished) Total microcystin (μg/L) (Midwest USA) n=791 Graham et al. 2004 U.S. Lakes Survey 2007 (USA) n=1253 200 (SE USA) n=702 Wilson (unpublished) (Midwest USA) n=254 Graham et al. 2006 Johnston & Jacoby 2003 (WA USA) n=59 150 Graham & Jones 2009 (Midwest USA) n=1402 N=4549 100 50 0 0 100 200 300 400 500 600 1100 1200 TN:TP
Toxins • Dermatoxins – Skin, rashes • Hepatotoxins http://www.mncenter.org/issues/water – Liver toxins • Neurotoxins http://www.bubblews.com/news/529637-liver-lover – Central nervous system http:// painprotherapeutics.com/conditions/neurological-pain /
Fernan Lake • Located in Kootenai County, near Coeur D’Alene, Idaho • 154 ha • 5.1 m mean depth • 8.2 m max depth
Bloom history Day/yr Action 26-Jul- 2007 Bloom noted 05-Aug-2008 Bloom noted 01-Oct-2008 Bloom noted 11-Jul-2012 10 day advisory 28-Jun-2013 24 day advisory 08-Jul-2014 14 day advisory 09-Sep-2014 90+ day advisory 26-Jun-2015 ongoing
Lake closures
Objectives • Establish detailed mass balance of phosphorus and total residue • Sample in- and outflows for 1 year
Inflows and outflow
Culvert locations
Determine culvert load F. Wilhelm
Determine wetland load
Explore influence of the dam 13-May-14 Dam in 01-Dec-14 Dam out 03-Mar-15 Dam in
ISCO automated samplers • One sample/day http://www.techrentals.com.au/ F. Wilhelm http://www.caeonline.com/listing/product/187711/isco-3700 http://w
Sample analyses • Total residue (mg/L) was measured using standard method 2450-B (Eaton et al. 2005) T. LaCroix • Total phosphorus ( μ g/L) was measured using method 4500-P (Eaton et al. 2005) H. Rajkovich
Discharge • measured by traditional cross-section and velocity • Concentration × discharge= load Depth (m) Distance (m)
Discharge Made rating curves from bi- 1.4 y=1.50x2.48 weekly visits R2=0.99 1.2 1.0 Discharge (m 3 /s) recorded stage 0.8 @ 15 min 0.6 0.4 intervals 0.2 0.0 http://www.onsetcomp.com/products/data-loggers/water-level 0.0 0.2 0.4 0.6 0.8 1.0 0 Stage(m)
Lake surface area and volume • Used bathymetry data • Water level at the dam • Combined with wet and dry deposition rates to calculate wet and dry deposition loads F. Wilhelm
A M F Fernan Creek Hydrograph J D N O S A J J M 6 6 5 4 3 2 1 0 3 ·s -1 ) Discharge (m
Fernan Creek Hydrograph 6 6 April 2014-April 2015 5 3 ·s -1 ) 4 Discharge (m 3 2 1 0 M J J A S O N D J F M A
Fernan Creek Hydrograph 6 6 Fernan Creek Outflow 5 Discharge (m 3 ·s -1 ) 4 ~ 3 day delay 3 2 1 0 M J J A S O N D J F M A
Fernan Creek Hydrograph 6 6 April 2014-April 2015 5 December 1999-December 2000 3 ·s -1 ) 4 Discharge (m 3 2 1 0 M J J A S O N D J F M A
Annual water budget Precipitation Precipitation 1.3x10 6 m 3 Road Culverts Evaporation Fernan Creek 1.8x10 4 m 3 -1.7x10 6 m 3 8.3x10 6 m 3 Recharge to Aquifer -2.0x10 6 m 3 Dam Groundwater/ -8.8 x10 6 m 3 Aquifer Seepage Net gain= 1.4x10 6 m 3 3.4x10 6 m 3
11-Mar-14 F. Wilhelm 14-Oct-14 T. LaCroix
11-Mar-14 F. Wilhelm
Total Phosphorus Flux 40 40 Fernan Creek Fernan Creek Total phosphorus (kg·day -1 ) Outflow 30 20 10 0 M J J A S O N D J F M A
Total Phosphorus Storage Input - Output = Δ Storage Inputs = 1.4 tonnes - Output = 0.3 tonnes Δ storage = 1.1 tonnes (81%)
Annual P budget Precipitation 145 kg Dry Deposition 99 kg Road Culverts Fernan Creek 1 kg 1125 kg Wetland 33 kg Dam -264 kg
Inflow P percentages Precipitation 10.2% Dry Deposition 7.03% Road Culverts Fernan Creek 0.07% 80.2% Wetland 2.4%
Total Residue (sediment) Input - Output = Δ Storage Inputs = 2298 tonnes - Output = 760 tonnes Δ storage = 1538 tonnes (67%)
6 April 2014-April 2015 5 -1 ) 4 3 ·s 93 % of TP load during Discharge (m spring Runoff 3 2 1 0 M J J A S O N D J F M A
Problem is in the summer months 6 6 April 2014-April 2015 5 -1 ) 4 3 ·s Discharge (m 3 2 1 0 M J J A S O N D J F M A
Calculate summer internal load in-out- Δ in lake P= L internal (Welch and Jacoby 2001) *This assumes that all external P is readily available
Summer P budget Precipitation Precip 15 kg Dry Deposition 37 kg Road Culverts d C d ulv Fernan Creek 0.08 kg 40 kg Wetland Internal Loading 20 kg 5-58 kg Dam -0.14 kg
Summer internal load In - out - Δ in lake P = L internal 93 - 0.14 - 88 +20 = 25 kg (21%) 93 - 0.14 - (88-15)+20 = 40 kg (30%) 93 - 0.14 - (88-15-38)+20 = 78 kg (46%)
Internal loading 2014 2015 258 mg·m -2 ·yr -1 71 mg·m -2 ·yr -1 2015 29 % lower 30 sites than deep site 50 mg·m -2 ·yr -1
Internal loading 2014 2015 183 mg·m -2 ·yr -1 50 mg·m -2 ·yr -1
What is the source? • Internal loading via anoxia / redox reactions No O 2
What is the source? • Fernan is well mixed throughout the year No O 2
Wind induced mixing
Biotic community recycling 3- PO 4 4 3- PO 4 3- 3- PO 4 3- PO 4 PO 4 3- PO 4 3 PO 4 3- P
Literature data • • 11 publications 11 publications • • rates ranged from rates ranged from 0.02 to 5.46 mg·m -2 ·day -1 0.01 to 37 mg·m -2 ·day -1 01 to 37 mg·m -2 ·day -1 0.02 to 5.46 mg 0.8 to 3.3 mg·m -2 ·day -1
Summary • Majority of P and sediment come in during spring runoff • However this is not the problem time period • Internal loading contributes 21-46% of the available P in summer • Investigate internal loading further
Summary • Inter-annual variability in runoff and loading • Wind mixing or biotic community • In-lake strategies in concert with whole-watershed remediation
Future directions • Wetland function • Dry deposition • Internal loading • Restoration/remediation
Remediation options Whole-w atershed/external • Headwater to lake (sed. delivery) • Examine Fernan Creek In-lake/internal • Dredging • Alum addition • Nitrogen addition
In-lake remediation • Treat symptoms, not the source • Expensive – commitment
Fernan Creek changes 1954 1974 Today Historic Fernan Creek Photos from USGS
Alum addition • Precipitates P from the water column • If alum is buried by sediment, it becomes ineffective • Whole lake application for Fernan Lake would cost between $22,500 - $560,000
Dredging • Remove P-rich seds • Need someplace for removed sediment
Geotubes to dewater sediment
Nutrient rebalance • Add N to re-balance TN:TP ratio • Allows beneficial algae to flourish • Reduces cyanobacteria abundance and toxins
Questions?
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